Functional modes of proteins are among the most robust

It is shown that a small subset of modes which are likely to be involved in protein functional motions of
large amplitude can be determined by retaining the most robust normal modes obtained using different
protein models. This result should prove helpful in the context of several applications proposed recently,
like for solving difficult molecular replacement problems or for fitting atomic structures into low-
resolution electron density maps. It may also pave the way for the development of methods allowing
us to predict such motions accurately.